Vast: The Fearsome Foes

Only if you move the Artifact or its carrier with Telekinesis, or if the carrier is a possessed player. A non-possessed player entering on their own does not lock it; see the Ghost rules, p. 3.

Lock 5 Artifacts onto Ghost tiles, then enter the Entrance tile. Once an Artifact is locked, it cannot be moved; see the Ghost rules, pp. 2, 4.

After rolling all three dice, choose two: the higher value is your movement points and the lower value is your attack points. The third die is unused that turn; see the Ghoul rules, p. 2.

They do not carry over: at the end of your turn, the Ghoul discs remaining on your Attack space become your Defense until your next turn begins. See the Ghoul rules, p. 3.

No. During an angry action, you cannot mark Crystal tiles or collect Treasures, so you cannot gain Radiance from them; see the Unicorn rules, pp. 2, 4.

After resolving the attack, you are forced to Teleport immediately, so you cannot mark the Crystal or collect Treasures at the attack space. See the Unicorn rules, p. 3.